Aliens in fiction are very similar to humans. On Star Trek they might have an extra bone in the face and in Avatar they’re blue, but they’re virtually identical to humans, while in some cases the aliens seem to be nothing more than pure energy. But these are fantasies produced by limited minds and not realistic ideas based on an in-depth understanding of what life is and why it is the way it is. I wanna know what aliens really look like. To find out I’m gonna try to figure out what aliens are made of, what they eat and how they reproduce, based on the facts we have about life on Earth.
1. What are aliens made of?
All life on earth; trees, virus, fungi, reptiles, insects, mammals are made from 4 molecules, adenine, thymine (uracil), guanine and cytosine. Just 4 small molecules that are all made from about 20 atoms each. And all 4 are made up of 4 atoms; Nitrogen, Carbon, Oxygen and Hydrogen. These 4 atoms are small and therefore common in the universe because small atoms are produced in stars. They dissolve in water and thanks to the liquid water on earth they had a good chance of meeting each other and react chemically to form life. There might be some silicon-based life-forms as well. Both carbon and silicon have 4 valence electrons, meaning they have the maximum ability to form molecules with other elements making them great candidates for a basis of life and silicon is a also a small and common atom in the universe.
Life on a different planet would benefit from a liquid that increases the potential for forming new molecules, a star that makes up a stable energy source, an atmosphere that protects from electromagnetic radiation that destroys molecules and lastly the necessary atoms that like to react, like carbon and silicon. Helium, the second most abundant element in the universe is very stable and non-reactive and therefore not a big part in life. On the other hand, Germanium also have 4 valence electrons but it is very rare in the universe and only through massive luck will there be a planet far out in the colder regions of the universe with large amounts of germanium, but it’s not impossible.
2. What will aliens eat?
The first forms of life breathed in carbondioxide, used photosynthesis (star power) and breathed out oxygen. This is the plant quality. Then we get bacteria that breathe the now bountiful oxygen and eat the plants or other “animal bacteria”, that’s the animal quality. These are the only two types of life on Earth. Either you eat photons or you eat photon-eaters or you eat photon-eater-eaters and so on.
It’s likely they’ll consume molecules from the planet together with either photons or heat from the planet (like reptiles). The life-forms are most likely to occur on the surface where the molecules can move around easily and not in a very warm molten core that destroys molecules. They might use e.g. iron-compound molecules as their main food – life on earth only needs a small amount of iron. But humans eat carbohydrate-compound molecules because of its abundance so carbon or silicon are still more likely. Note that all food humans eat is other life-forms (except water) and the energy from these carbohydrate-compound molecules originally comes from photosynthesis.
On Earth, mammals are the biggest life-forms on the surface and in the water but not in the air. The evolution is like this: Plant bacteria, followed by animal bacteria, followed by different sorts of invertebrates, then insects, then fish, then reptiles, then flowers, then some reptiles got feathers and wings and they rule the air still today. When a lot of reptiles died 65 million years ago, small mammals took over. They differ from insects and reptiles and fish in that they have large brains and require much more from their parents. The female mammal only have 1-20 children, carries them inside her own body for several months and when it’s born let’s it eat from it’s own body, energy in the form of milk, and then spends several years with the child to educate its brain. This requires a lot, but is worthwhile in the end as we can see in the evolutionary success of whales and humans.
3. What will they look like?
Alien animals will have senses; trees don’t but all tree-eaters, except fungi, bacteria and virus, do. And senses are required for thought so they’re not animals if they don’t have senses. And they will reproduce by some form of molecular copying or they’re not really life. And they will use energy to move around. They might not have milk, they might not have sex, they might not have eyes, they might not be symmetrical (all reptiles, birds, mammals have 4 extremities, 2 on each side on the body), they might not have a head that functions like a human head. Human heads are a center for senses – taste, smell, sight and hearing – and they take in air, water and food through the hole in the head. (Most birds, fish, reptiles, mammals, insects, spiders do too. Some lizards drink with their skin. Also octopuses, which belong to neither of these groups and interestingly have beaks, are what in Swedish is known as huvudfotingar (“head-feeters”) see picture below).
Animals on earth have between 0 and many extremities. Mammals, reptiles and birds have 4 extremities, one main body with processing organs and a head for molecular intake and senses, a skeleton that supports it all and skin that protects it all and holes at the bottom for passing out DNA and poo. And don’t forget all the bacteria that live in symbiosis with us inside us and on our body surface.
Aliens on other planets might swim with a screw-like body, sense radio waves with their skin, which might be made of iron. They might be 5000 meters long and have tree-like extremities and fight for mating rights using electromagnetic radiation or do they reproduce asexually, polysexually or maybe using flowers? In an area of rainforest 100x100metres you can find 100 000 species (not individuals) of insects. They all look “alien” to us and we should expect the same biodiversity on other planets, especially planets where life has evolved long enough to produce intelligent life. So, given the probability of all the prerequisites for life listed above, what will aliens look like? They might have senses for detecting all kinds of strange things in nature, shapes and life-cycles that we can’t even dream of, and made from a molecule no less strange than the billions-of-atoms-long DNA-molecule.
We can’t know what they’ll be like but if you see an alien with a head, two eyes and a mouth you should be be skeptical. We can’t know but maybe they’re as strange as the offspring of a rose, a scorpion, a star fish, an algae, a snail and a diamond. And potentially 10 000 times smarter than us, and if so, they will have the capacity to alter their DNA and their bodies to even stranger appearances, although they still have to obey the laws of physics and chemistry.
Tags: aliens, DNA, elements, molecules, planets, reproduction, stars
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